If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Great 3D game where you find yourself in the American Civil War. Your task will be to control the gun and fire on arriving enemies. They will walk in medium-sized groups, so you have to guess the distance and set up properly the cannon.
A/Arrow left - Aim left.
D/Arrow right - Aim right.
W/Arrow up - Aim upwards.
S/Arrow down - Aim downwards.
Mouse - Aim, left click to fire.